1. UROGENITAL
SYSTEM
Chapter 11

2. UROGENITAL SYSTEM
 Combination of excretory and reproductive
system.
 Kidney is the main excretory organ of
vertebrates.
• Concerned with the elimination of metabolic waste
products.
 Ovary is the female reproductive organ or
gonad.
 Testis is the male reproductive organ.
• These are concerned with the production of the
reproductive cells (egg and sperm).
 Ducts are passageways for the excretory
waste products and reproductive cells from
where they are produced to the outside.

3.  Ductsof
excretory and
reproductive
systems are
intimately
associated

4. EXCRETORY SYSTEM
 Waste products of metabolism include:
urea, ammonia, uric acid, creatinine,
various pigments, inorganic salts, and
water.
 These are excreted through the kidney.
 Nephrons are the functional units of the
kidney, where the blood is filtered with
these metabolic wastes.
 Metabolic wastes pass to the outside
through ducts.

5. ARCHINEPHROS/HOLONEPHROS
 Excretory organ of primitive
vertebrate ancestors.
 It is composed of paired
archinephric ducts, located
on the dorsal side of the body
cavity and extending the
length of the coelom.
 Each duct has a pair of
tubules to a segment.
 The tubules open into a
coelom through the
nephrostome.

6. ARCHINEPHROS
 External glomeruli
drain the coelomic
fluid and are located
in close proximity to
the nephrostome.
 Larvae of hagfish and
caecilians have this
type of excretory
organ.
 Tissue fluid discharge from
glomerulus
>coelom>nephrostomes>tubules
>archinephric ducts>to the
outside.

7. THE ANAMNIOTE KIDNEY:
PRONEPHROS
 1st embryonic tubules in
all vertebrates
 called pronephric
tubules because they are
the 1st to develop & are
anteriorly located
 The duct that drains the
pronephros is called the
pronephric duct.
 The pronephros is
temporary & function
only until glomeruli &
tubules further back
become functional.

8. THE ANAMNIOTE KIDNEY:
PRONEPHROS
 Some have external
glomerulus, while
most have internal
glomeruli.
 Internal glomeruli are
small knots of arterial
capillaries surrounded
by the Bowman’s
capsule.
 Renal or Malphigian
corpuscle is composed
of the glomerulus and
the Bowman’s capsule

9. THE ANAMNIOTE KIDNEY:
PRONEPHROS
 Bloodafferent
arterioleglomerulus
efferent arteriole
postcardinal vein
heart
 Filtrate of blood plasma-
glomeruluscoelom or
cavity of the Bowman’s
capsuletubule
pronephric ductcloaca
 Selective reabsorption of
water and other
constituents may occur as
fluid passes down the
tubule.

10. THE ANAMNIOTE KIDNEY:
PRONEPHROS
 Pronephric tubules
function only until the
end of the larval stage in
amphibians and
equivalent stage in fishes.
 Glomus is the term for
several united glomeruli.
 Pronephric chambers
are larger chambers
formed by expansion of
the pronephric tubules.

11. THE ANAMNIOTE KIDNEY:
OPISTHONEPHROS
 The kidney mass caudal to pronephric region
 Functional adult kidney of lampreys, most fishes
and amphibians
 Drained by mesonephric (archinephric) duct
 Mesonephrossimilar to opisthonephros but
mesonephros is the structure that appears during
embryonic development in reptiles, birds, and
mammals.
 When it serves as an adult kidney, it is sometimes
called opisthonephros.

12. FATE OF NEPHROGENIC MESODERM (RED) (BOOK FIGURE
15.8).

13. THE ANAMNIOTE KIDNEY:
OPISTHONEPHROS
 It is different from
pronephros because it
lacks segmental tubules
that is exhibited by the
pronephros.
 Kidney tubules and
coelom are rarely
connected.
 Renal corpuscles with
internal glomeruli are
typically present.

14. THE ANAMNIOTE KIDNEY:
OPISTHONEPHROS
 An opistonephric
tubule has a narrow
neck adjacent to the
renal corpuscle.
 Neck is followed by
the:
 collecting portions,
which joins the
archinephric duct
and;
 secretory part,
which forms the
proximal and distal
convoluted tubules.
Urogenital organs of male salamander,

15. THE ANAMNIOTE KIDNEY:
OPISTHONEPHROS
 Ureter-like duct is
formed by the union of
collecting ends of
several collecting
tubules.
 This may open into
the archinephric duct
or may connect
independently with
the cloaca.

16. THE ANAMNIOTE KIDNEY:
OPISTHONEPHROS
Opisthonephric kidneys of
fishes
 Males have longer kidneys
than females.
 Efferent ductules connect the
testes with the archinephric
duct.
 Archinephric duct becomes the
ductus deferens which serve
for sperm transport.
 Female fishes have the
posterior ends of their
archinephric ducts enter a
common urinary sinus inside
a small urinary papilla.

17. THE ANAMNIOTE
KIDNEY:
OPISTHONEPHROS
 Urinary papilla
enters the cloaca in
sharks.
 It opens directly to
the outside in fishes
without cloaca.
 Seminal vesicles and
sperm sacs may
develop for the
temporary storage of
spermatozoa.

18. THE ANAMNIOTE KIDNEY:
OPISTHONEPHROS
Opisthonephric kidneys of
Anurans
 Tubules are more
concentrated on the
posterior end and are
confined to the posterior
part of the abdominal
cavity.
 Dorsally located,
retroperitoneal, and dorso-
ventrally flattened
 Kidneys of the females have
no relation to the
reproductive system.

19. THE ANAMNIOTE KIDNEY:
OPISTHONEPHROS
Opisthonephric kidneys of
Anurans
 In males, certain anterior
kidney tubules became
modified as efferent
ductules/vasa efferentia.
 They connect the testis with
the kidney .
 Archinephric duct
serves to transport
spermatozoa and urine.
 Urinary bladder is
thin-walled and serve for
the temporary storage of
urine.

20. THE AMNIOTE KIDNEY
 Three types of kidneys
that appear in succession
during embryonic
development of amniotes
are: pronephros,
mesonephros, and
metanephros.
 The metanephros
persists to become the
adult kidney.
 Pronephros appears in
the very early stages of
development but soon
degenerates.

21. THE AMNIOTE KIDNEY
 Mesonephros develops
as the embryonic kidney
in reptiles, birds, &
mammals
 It is sometimes called the
Wolffian body and the
mesonephric duct is called
the Wolffian duct.
 It functions for a short
time after hatching or
birth

22. THE AMNIOTE KIDNEY
 Wolffian duct serves as
urinary passage but when the
metanephros becomes
functional, it degenerates in
the female, but persists in the
male.
 Remnants of the
mesonephros are associated
with the reproductive system.
 This include the epididymis,
ductus deferens, seminal
vesicle, paradidymis, and
ductus aberrans in the male.
 In females, remnants include
the epoophoron and
paraoophoron in the dorsal
mesentery of the ovary, and
canal of Gartner in the
mesentery of mammalian
oviduct.

23. THE AMNIOTE KIDNEY:
METANEPHROS
 Arise posterior to the
mesonephros.
 Nephron is the functional
unit.
 Each nephron is composed
of renal corpuscles,
secretory tubules, and
collecting tubules.
 Differentiation of
metanephros begins when a
metanephric bud sprouts
from posterior end of the
mesonephric duct.
 Nephrogenic mesoderm
surrounds the bud.

24. THE AMNIOTE KIDNEY:
METANEPHROS
 Bud grows anteriorly together with the
metanephric blastema, and eventually gives
rise to metanephric duct or ureter, and
pelvis of the kidney.
 Fingerlike outgrowths from the pelvis invade
the kidney blastema and become collecting
tubules.
 S-shaped tubules are organizing within the
blastema.
 One end grows toward and encapsulates a
glomerulus to form a renal corpuscle.
 The other end grows toward and empties into a
collecting tubule.

25. THE AMNIOTE KIDNEY
 Each kidney tubule
of mammals is
composed of the
following parts:
 Proximal
convoluted tubule
 Loop of Henle with
ascending and
descending
portions
 Distal convoluted
tubule.

26. THE AMNIOTE KIDNEY
 Capsule is a connective
tissue that surrounds the
kidney.
 Cortex is the outer kidney
substance containing renal
corpuscles.
 Medulla is the inner
substance which contains the
loops of Henle and common
collecting tubules
 Renal pyramids are the
conical aggregated loops and
collecting tubules.
 Renal papilla is a blunt tip
of each renal pyramid that
project into a funnel-shaped
outpocketing, the calyx of
the pelvis.

27. COMPARATIVE ANATOMY OF THE
METANEPHROS
Reptiles
 Kidneys restricted to
the posterior half of
the abdominal cavity
and confined to the
pelvic region.
 Generally small and
compact, with
lobulated surface.
Urogenital system of female sphenodon

28. COMPARATIVE ANATOMY OF THE
METANEPHROS
Birds
 Kidneys located in the
pelvic region of the
body cavity, with the
posterior ends usually
united.
 Lobed structures with
short ureters which
open into the cloaca. Male bird’s urogenital system

29. COMPARATIVE ANATOMY
OF THE METANEPHROS
Mammalian kidney
 Compact, bean-
shaped organ
attached to the body
wall.
 Ureter leaves the
hilum or hilus.
 Hilum is also the
part where blood
vessels and nerves
enter and leave the
kidney.

30. URINARY BLADDER
 Embryonic origin: ventral cloacal wall and
portion of the allantois.
 Function: temporary storage of urine before
disposal or voiding
 It may serve as a reservoir of water in
terrestial vertebrates.
 Water, reabsorbed from the bladder results
from the action of an andiuretic hormone.
 This is important to prevent dehydration.
 In some lower vertebrates, it may serve as
recovery sites for some ions that are scarce in
their niche.

31. URINARY BLADDER: FISHES
 It is an insignificant
enlargement of the
conjoined posterior
ends of the urinary
ducts.
 Not significant
because fishes are
immersed in water.
 Many marine fishes
can extract fresh
water from sea water
by drinking sea water
and quickly excreting
the salts.

32. URINARY BLADDER
Amphibians
 Large and thin
walled
 It connects with
the cloaca a short
distance beyond
the openings of the
archinephric ducts.

33. URINARY BLADDER
 Crocodilians, snakes, Turtles
some lizards, and  With a pair of
birds do not have
urinary bladder. accessory urinary
bladders which is
Birds connected with the
 Absence in birds reduces
cloaca, and functions
the energy requirements as accessory organs
for flight. for respiration
 Urinary wastes, mainly
 These may be filled
in the form of uric acid
are eliminated via the with water in females,
cloaca along with the which is used to soften
feces. the ground in
preparing a nest.

34. URINARY BLADDER
Mammals
 Present in all
mammals.
 It is muscular and
connects to the
outside by the
urethra
 Lower ends of
ureters opens
directly into the
bladder on its
posterior dorsal
surface.

35. URINARY BLADDER
 Much of the muscles of the
bladder continues down into
the urethra.
 In males, the urethra is longer
and passes through the penis
and open at the tip through
the external urethral
orifice or meatus.
 Female rats and mice have
their urethra that opens
independently to the outside,
passing through the clitoris.
 In other mammals, the
urethra enters a urogenital
sinus or vestibule.

36. EFFECT OF ENVIRONMENT ON
KIDNEY STRUCTURE AND
FUNCTION
 Kidney is not only  Vertebrate kidneys
involved in waste have adaptations to
elimination but also their environments
involved in the  Size of glomeruli is
maintenance of water related to the amount
balance in the body. of filtrate removed
from the blood.
 Regulates the amount
 Larger glomeruli
of water given off in indicates an increase
the urine and controls of filtrate moving out
the amount of salts from the blood into
the kidney tubules.
and other electrolytes
eliminated through
the urine.

37. EFFECT OF ENVIRONMENT ON
KIDNEY STRUCTURE AND
FUNCTION
 Terrestial forms have
reduced glomeruli.
 Marine teleosts do not
have glomeruli in
their kidneys.

38. EFFECT OF ENVIRONMENT ON
KIDNEY STRUCTURE AND
FUNCTION
 Kidney tubules vary  The distal convoluted
among vertebrates but tubule is involved in ionic
all have proximal and water reabsorption.
convoluted tubule  Amphibians have a degree
 Aglomerular of selective reabsorption in
kidneys of marine their distal convoluted
teleosts have their tubule.
proximal convoluted  Reptiles, birds, and
tubule as the only mammals have tubules in
functional, but their their kidneys but their
urine does not differ development depends on
from the urine of the amount of water
fishes with glomeruli. available to the animal.

39. EFFECT OF ENVIRONMENT ON
KIDNEY STRUCTURE AND
FUNCTION
 In desert forms, the
distal convoluted
tubules are very long
and are capable of
resorbing nearly all
water, so they have a
very concentrated
urine.
 Animals which are
accessible to water
sources have shorter
tubules and their
urine is less
concentrated.

40. EXTRARENAL SALT EXCRETION
 Present in vertebrates that live in salt-rich
environment or that live in arid
environments.
 Chloride-secreting glands are present on
the gills of marine fishes.
 Rectal glands are present in
elasmobranchs.
 Nasal or orbital glands are present in
marine reptiles and birds that feed on fish
from salt water.
 Sweat glands in mammals eliminate some
salt of the body.

41. REPRODUCTIVE SYSTEM
 Vertebrates exhibit sexual
reproduction.
 Zygote results from the union of male
and female gametes.
 Ova and spermatozoa are produced in
the gonads, the testes and ovaries
respectively.
 Gonads are derived from the mesoderm.
 Deferent ducts in male, and oviducts in
female transport gametes to the outside of
the body.

42. REPRODUCTIVE SYSTEM
 Deferent ducts are usually the
archinephric or the Wolffian ducts which
also transport urine from the kidney.
 Wolffian ducts in amniotes persists to
become the ductus deferens.
 Accessory sex organs bring the germ
cells together.
 Reproductive ducts
 Associated glads
 Intromittent or copulatory organs.

43. FEMALE REPRODUCTIVE
SYSTEM

44. OVARY
 Two layer of a typical ovary
in mammals are:
1. cortex, outer with
developing Graafian
follicles.
- ovum with each follicle is
nourished by follicular cells.
- at maturity, certain
follicles push to the surface
of the ovary and either
rupture to liberate the
ovum (ovulation), or are
reabsorbed.
2. medulla, which is inner and
made up of connective
tissue, blood vessels,
lymphatic vessels, smooth
muscle, and nerve fibers.

45. OVARY
 Ovarian follicles vary
in size depending
upon the season when
it is examined and
upon the volume
characteristic of each
species.
 Larger ova in lower
forms because of their
yolk content.
 Ovary attains
maximum size during
the breeding season in
some vertebrates

46. OVARY: FISHES
 Paired or fused.
 Only the right ovary fully
develops and the left
degenerates in some
elasmobranchs.
 Most teleosts have
saccular type ovaries
which produce large
number of ova during the
breeding season.
 Ripe ova-->central ovarian
cavity--->oviduct--->outside
 Adult teleosts lack cloaca
and have separate openings
from urinary and digestive
systems.

47. OVARY: FISHES
 Most are oviparous
while others are
ovoviviparous.
 Some have fertilized
eggs that develop
while inside the
ovarian follicles
 Others have their
young that develop
within the cavities
of the ovaries.

48. OVARY: AMPHIBIAN
 Saccular
 Ova escape into
the coelom through
their external
walls.
 Shape varies with
the shape of the
body.
 Fat bodies are
closely associated
with the ovaries.

49. OVARY: REPTILES
 Snakes and lizards’
ovaries are saccular
and elongated.
 Turtles and
crocodilians have
solid ovaries.
 Certain
ovoviviparous
snakes and lizards
have corpora lutea
that form from
ruptured follicles
after ovulation.

50. OVARY: BIRDS
 Both ovaries are
present in embryonic
development.
 In most birds, the
right ovary
degenerates, and the
left becomes the
functional gonad.
 Stigma or cicatrix is
a band located on the
surface of the follicle
through which mature
ova escape from the
ovarian follicles into
the coelom.

51. MAMMALIAN OVARIES
 Located in the lumbar or
pelvic region.
 Considered small in
relation to the size of the
body of mammals.
 Placental mammals have
compact ovaries with an
antrum within the
graafian follicles.
 Covered by germinal
epithelium from which
oocytes arise.
 Some of this oocytes
become mature ova
during the life of the
individual.

52. MAMMALIAN OVARIES
 Ovum escape the ovary
when the wall of graafian
follicle ruptures.
 Cells that remain after
follicle rupture organize to
form corpus luteum.
 Corpus luteum is one
source of progesterone
needed to maintain
pregnancy.
 Before ovulation, estrogen
is the predominant
secretory products of the
follicle cells.
 Atretic follicles are those
that fail to rupture and
degenerate.

53. OVIDUCTS
 Modifications of the
Mullerian ducts, which
degenerates in the males.
 Differentiates into
regions .
 Posterior portion expands
to become the uterus.
 Serves as temporary
storage site for eggs or a
place where the young
develops.

54. OVIDUCTS: FISHES
 Some teleosts have
modified abdominal
pores where eggs escape
from the coelom.
 Elasmobranchs have
ostium tubae, which
opens into the coelom.
 Narrow distensible
oviduct on either side.
 Shell gland is an
enlargement of the
oviduct.
 Beyond the shell gland
is the uterus that opens
into the cloaca.
 Ovisac shelters and
nourishes the embryo in
viviparous species.

55. OVIDUCTS: AMPHIBIANS
 Paired, elongated tubes with
ostia.
 Enlarged posteriorly to form a
short uterus or uterine
enlargement .
 Uterus opens independently
into the cloaca.
 Uteri in most amphibians serve
for temporary storage for ova.
 Lining of the oviducts have
glands that secrete jellylike
material to envelop the passing
eggs.
 Fertilization is external
 Male grasp the female in
amplexus.

56. OVIDUCTS: REPTILES
 Open into the coelom through slit-like ostia.
 Turtles and crocodilians have glands in the upper part that
secrete albumen.
 Shell is deposited in the uterus or shell gland in snakes and
lizards.
 Uteri enter cloaca independently.
 Fertilization occurs in the upper part.
 Some snakes and lizards are oviparous.
 Other reptiles are ovoviviparous.

57. OVIDUCTS: BIRDS
 Most except birds of prey
have only the left oviduct
that is functional.
 Long, coiled, and consists
of several regions.
 Ostium is bordered by
fimbriae.
 Albumen is secreted by
the glandular portion.
 Isthmus is found Oviduct of a laying hen
1 Infundibulum,
posterior to the glandular 2 Magnum,
portion where inner and 3 Isthmus,
outer shell membranes 4 Shell Gland,
are deposited around the 5 Uterus with egg
albumen. inside

58. OVIDUCTS: BIRDS
 Uterus or shell
gland is where the
hard calcareous
shell of the egg is
formed.
 Uterus opens into
cloaca.
 Fertilization is
internal and
accomplished by
cloacal kiss.

59. OVIDUCTS: MAMMALS
 Paired, with various
degrees of fusion between
the two sides.
 Three distinct regions in
some: narrow oviduct or
fallopian tube, the
expanded uterus, and a
terminal vagina.
 Cervix is the narrow
lower part of the uterus
which leads into the
vagina.
 Opening of the uterus
into the vagina is called
os uteri

60. OVIDUCTS: MAMMALS
 Marsupialshave
paired duplex uteri
and paired vaginae.

61. OVIDUCTS: MAMMALS
 Other placental mammals
have horns of the uterus,
uterine body, and a single
vagina.
 Uterus are classified:
1. Bipartite when there are
two complete lumens
within the body of the
uterus.
2. Bicornuate uterus has a
single lumen within the
body and with two horns
3. Simplex, has no uterine
horns, and the vagina
opens directly into the
body.

62. OVIDUCTS: MAMMALS
 Body of simplex uterus is
where the fetus become
implanted.
 Uterine wall is made up of:
1. Endometrium – uterine
lining which becomes highly
vascular under the stimulus of
hormones.
2. Myometrium – thick
muscular layer
3. Visceral peritoneum – thin
outer serous membrane.
- Menstruation results from
degeneration or sloughing of
the uterine lining followed by
hemorrhage from blood
vessels.
- Estrogen and progesterone
control these endometrial
changes.

63. OVIDUCTS: MAMMALS
 Vagina is the fused terminal
portion of the mullerian
ducts.
 It opens into a urogenital
sinus.
 Higher primates’ vagina
extends almost to the
exterior, opening into a
shallow vestibule.
 Lining of vagina is cornified
for reception of the penis.
 Marsupials have a median
vagina which continue as
paired lateral vaginae.
 Penis of male marsupials is
forked at the tip.

65. MALE REPRODUCTIVE
SYSTEM

66.  Functions of the  Scrotum
male • A sac containing the
reproductive testes
system are: • Intrascrotal
 Production of sperm temperature is kept
cells constant by two sets
 Sustaining and of muscles:
transfer of the • Dartos: smooth
sperm cells to the muscle that wrinkles
female scrotal skin
 Production of male • Cremaster: bands of
sex hormones skeletal muscle that
elevate the testes

67.  Testes
 Seminiferous
tubules “sperm
factories”:
 Produce the sperm
 Mature
spermatozoa will
move to the rete
testis  efferent
ductules
epididymis
ductus deferens
 Also an endocrine
gland as they
produce
testosterone

68. ELASMOBRANCHS’ TESTES
 Paired symmetrical
structures
 Suspended by
mesorchium
 Other fishes have
elongated and
lobulated testes.

69. AMPHIBIAN TESTES
 Shape corresponds to
body shape
 Elongated in
caecilians, short or
irregular in urodeles
 Oval or rounded and
more compact in
anurans

70. REPTILES’ TESTES
 Oval rounded or pyriform compact structures
 Snakes’ and lizards testes’ have onetestes that
occupies farther forward in the body cavity than the
other

71. BIRDS’ TESTES
 Oval or round-shaped
and changes in size
depending on the
period of the year.

72. MAMMALIAN TESTES
 Tunica albuginea a thin
tough fibrous envelop of the
testis
 Scrotum serves to regulate
the temperature ideal for the
testes to be able to produce
viable sperm cells
 Vaginal sac is a diverticulum
of the peritoneum into the
scrotum
 Tunica vaginalis is the
extension from vaginal sac .
that comes in close contact
with the tunica albuginea

73. MAMMALIAN TESTES
 Maybe found in the pelvic
region or descend into a
scrotum
 Some mammals’ testes
descend into the scrotum
only during the breeding
season
 inguinal canal - passage
between abdominal
cavity & scrotum

74. SPERMATOZOA
 Vary in vertebrates
and are several times
smaller than the ova
 All possess tails for
locomotion
 Number produced by
the human male is
about 4ml or 300
million per ejaculation
 Boar produces about
½ liter

75. MALE GENITAL DUCTS
 Some fishes (e.g., gar
& sturgeon) &
amphibians -
mesonephric duct
transmits sperm &
urine
 Some amphibians -
mesonephric duct
transports only
sperm; new accessory
urinary duct drains
the kidney

76. MALE GENITAL DUCTS
 Sharks - mesonephric
duct is used primarily
for sperm transport;
accessory urinary duct
develops
 Teleosts -
mesonephric duct
drains kidney;
separate sperm duct
develops
 Amniotes - embryonic
mesonephric ducts
transport sperm in
adults

77. 1.Testis / testicles (present as a pair)
2. Ductus epididymidis (a pair)
3.Deferent duct / Vas deferens (a pair)
4. Ampulla of the deferent duct (a pair)
5. Glandula vesiculosa / Seminal gland
(a pair)
6. Ejaculatory duct (a pair)
7. Prostate (single)
8. excretory duct of the prostate
(several present)
9. Bulbourethral gland (Cowper's
glands) (a pair)
10. Urethral gland (Littre's gland)
(several)
11. Urethra (single)
12. Urinary bladder(single)

78. COPULATORY
ORGANS/INTROMITTENT ORGANS
 Found in vertebrates
that practice internal
fertilization
 Used for introducing
sperm into the female
reproductive duct
 cartilaginous fish -
appendages of pelvic
fins called claspers
direct sperm into
female reproductive
tract

79. COPULATORY
ORGANS/INTROMITTENT ORGANS
 snakes & lizards -
have pair of
HEMIPENES
(pocketlike diverticula
of wall of cloaca)
 turtles, crocodilians, a
few birds, & mammals
- exhibit an unpaired
erectile penis

80. COPULATORY
ORGANS/INTROMITTENT ORGANS
 penis - usually a  mammals (except
thickening of floor of monotremes) - penis
cloaca consisting of extends beyond body
spongy erectile tissue  The embryonic corpus
(corpus spongiosum becomes a
spongiosum) with tube with urethra
grooves to direct inside & 2 additional
sperm & ending in a erectile masses
glans penis (sensory develop (corpus
endings that reflexly cavernosa).
stimulate ejaculation)

82. END …QUIZ/RECITATION
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